Misfire

[robjamez]

Cylinder head back on, clean fuel in the tank and primed and she's alive! And sounds great without an exhaust on

3/4 alive, anyway. There's a misfire on cylinder 1, but it's not persistent, i.e it does fire on and off. Plug's sparking OK and I'm guessing that as it does fire sometimes the compression isn't the problem so could it be the carb?

Thanks.

[CD]

Swap the coils over. Check all choke plungers are seating down properly. Look for vacuum leaks. If the fault stays the same check the cam clearances.

[robjamez]

Thanks v much, I'll try that lot. Speaking of vacuums, I've got a set of pipes that connect to the back of the carbs - 4 into 2 into 1, which go nowhere. Are they just breathers or vacuums? Thanks!

[robjamez]

Aha, it's the overflow.